Table 1.

Strains with increased expression of efflux-associated genes, their susceptibilities to antibiotics and dyes, and their mutations in regulatory genesa

Strain Origin MIC (μg/ml) of:acrB mRNA expression acrR mutation marA mRNA expressionmarR mutation soxS mRNA expression soxR mutation
Antibiotics Dyes
CIP TETCHL CEF ACR ET BR
I113NCTC 10418 0.015 2 4 4 >512>512 wtwtwtwtwtwt
I114 NCTC 105380.06 4 8 8 >512 >512 wtwt wt wt
I87 MAFF 2256 128 16 512 >512 R45→Cwt wt
I88 MAFF 2>256 128 16 >512 >512 R45→Cwt wt
I89 MAFF 2>256 128 16 >512 >512 R45→Cwt wt
I236 Spain 32256 128 4 32 512 wtwt Silent
I237 Spain 16256 256 4 512 512 R45→Cwt R71→S
I238 Spain 4128 256 8 >512 >512 R45→Cwt wt
I239 Spain 2128 256 8 >512 512 R45→Cwt wt
I241 Spain 2128 128 16 >512 >512 wtwt wt
I242 Spain 4 28 32 >512 >512 wt wtS31→A; R90→G
I244 Spain 32 4 88 512 >512 wt wtwt
I245 Spain 8 4 8 8 512>512 wt wt wt
I246 Spain 8 128 256 4 16 128wt wt wt
I248Spain 8 4 8 8 >512 >512 wtwt Insert
I251 Spain 8>256 128 4 512 >512 wtwt Insert, L65→V
I253 Spain32 >256 256 32 >512 512 wtwt wt
I254 Spain 128 4256 8 >512 >512 Insertion wtThree frame shifts, N25→Q
I276 Argentina32 128 8 4 32 512 wt Y137→H wt
I278 Argentina 8 88 4 >512 >512 wt Y137→H wt
I279 Argentina 8 2568 4 256 >512 wt Y137→H wt
I280 Argentina 32 1288 4 >512 >512 wt Y137→H wt
I283 Argentina 32 2568 8 512 64 wt Y137→Hwt
  • a Abbreviations: CIP, ciprofloxacin; TET, tetracycline; CHL, chloramphenicol; CEF, ceftazadine; ACR, acriflavine; ET BR, ethidium bromide; wt, wild-type; MAFF, Ministry of Agriculture, Fisheries and Food. ↑, overexpression.